1. Field of the Invention
The present invention relates generally to fluid-tight quick disconnect couplings and more specifically to a quick disconnect ball joint coupling in which the conduits through which fluid flows to each half of the coupling may be misaligned and/or rotated when the coupling is engaged.
2. Prior Art
Quick disconnect couplings which must accommodate misaligned conduits are commonly provided in the form of a combined quick disconnect and ball joint. The ball joint coupling is typically held in engagement by means of a large misalignment ball which is locked by a plurality of small locking balls or by a sleeve which has an arched interior surface compatible with the diameter of the misalignment ball. While both of these prior art ball joint configurations permit both misalignment and rotation, they suffer from a number of inherent disadvantages which can preclude their usefulness. By way of example, those prior art combined quick disconnect and ball joint couplings in which the misalignment ball is held in place by a plurality of locking balls can, at particularly high pressure levels, result in the smaller locking balls being embedded into the surface of the larger misalignment ball. On the other hand, some prior art combined quick disconnect and ball joint couplings utilize a sleeve instead of locking balls to secure the misalignment ball in place while distributing the locking contact stress over a much wider surface area. However, these prior art couplings suffer the disadvantage of substantially increased rotational friction, thereby requiring a very high torque to rotate the coupling at high fluid pressure levels. There is therefore an existing need for an improved quick disconnect ball joint coupling in which the point of contact stress levels are reduced, but which at the same time requires only a relatively low torque to enable relative rotation between the male and female members of the quick disconnect.
Prior art relevant to the present invention includes the following United States patents:
U.S. Pat. No. 3,420,497 to Wilcox is directed to a misalignable fluid quick disconnect coupling. A nipple portion terminates in a bulbous spherical section which when captured within the nipple-receiving passage allows relative angular displacement of the nipple relative to the coupling housing. Leakage of fluid is prevented by an O-ring and a seal ring, while the spherical end portion of the nipple is retained within the passage by a plurality of locking balls, which are displaceable within the passage by the axial displacement of a sleeve.
U.S. Pat. No. 2,848,255 to Klein et al is directed to a lubricant fitting for coupling with a grease fitting. The lubricant-receiving fitting has a spherical bulbous head which is received within a cylindrical socket of the coupler body. The coupler is locked on the head of the fitting by the split ring which rides past the collar of the head, but sufficient axial force can be applied to quickly separate the two.
U.S. Pat. No. 4,269,226 to Allread is directed to a breakaway fluid coupling separable by pivotal movement of one coupling part relative to the other. The male coupling part is provided with a spherical segment sealing surface and a spherical segment locking surface which allows pivotal movement of the male portion relative to the female coupling portion. However, if in addition to the swivel force, a tension force is applied, the coupling will separate.
U.S. Pat. No. 3,997,197 to Marsh et al is directed to a ball and socket pipe coupling. The coupling member is provided with a spherically-shaped ball-like enlarged portion which is received within the spherical shaped socket portion of coupling member. The ball and socket arrangement allows the central axes of the coupling members to be inclined at an angle relative to each other while still maintaining a fluid-tight connection. A plurality of jaws or cam members are circumferentially disposed about a housing and pivotably movable to permit a socket of the housing to freely receive the spherically-shaped forward side of the enlarged portion for making engagement therewith.
U.S. Pat. No. 3,450,421 to Hatwell Jr. is directed to a combined flexible joint and remotely connectible and disconnectible union. The ball connector includes a tubular conduit having a ball member for releasable locking engagement with the ball housing member coupled to a second tubular conduit. When the ball is locked within the coupling, the conduits are free to pivot 10 degrees in any direction while a quick disconnect operation is performed by displacing a bearing ring.
U.S. Pat. No. 4,703,958 to Fremy is directed to a quick disconnect type coupling having a radially acting bolt. The balls act against a cylindrical bolt for locking the male member therein.
U.S. Pat. No. 3,606,393 to Huntsinger et al is directed to a pipe connection for underwater well head equipment. Of interest here, is the split retaining ring adapted to engage an external pin groove, and includes a spring bias provided by the coil compression spring which acts against a pin.
U.S. Pat. No. 4,413,846 to Oetiker is directed to a hose coupling with a latching mechanism. As shown in FIG. 1, the coupling includes a latching member and a safety locking member, both having a relatively flat configuration which engage the male coupling member under spring bias.
U.S. Pat. No. 3,944,263 to Arnold is directed to a dynamic pipe coupling having pressure operated seals. The socket portion of the ball type coupling includes three annular seals, each being biased against the ball of the mating portion by means of fluid pressure, as opposed to spring bias balls.
U.S. Pat. No. 2,550,536 to Delano, Jr. et al is directed to a high-pressure ball and socket pipe joint. Of interest here, is the flat ring which is biased by a plurality of spring washers. However, the flat ring is utilized for applying pressure to the packing rings, as opposed to retaining the ball member within the socket member.